This is a working overview of thymalfasin, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-03-09. Anything still debated is marked as such rather than presented as settled.
Several names appear in the literature for this peptide, including thymalfasin and the abbreviation T-alpha-1. Naming conventions differ among research articles, regulatory documents, and supplier catalogs, which complicates literature searches. Both synthetic and recombinant production routes yield a peptide with the same 28-residue sequence as the thymic isolate. Because the thymosin label also covers unrelated peptides, sources should be compared by sequence rather than by name alone.
The peptide occurs naturally in thymic tissue and has been detected in serum and other biological fluids. Reported concentrations are low, and reliable measurement generally requires immunoassay or mass spectrometry with an enrichment step. It is released from a larger precursor, prothymosin alpha, by proteolytic cleavage, although the enzymes involved are not fully characterized. Whether circulating levels reflect thymic output specifically remains an open question.
The peptide is generated in cells by cleavage of prothymosin alpha, a larger acidic protein encoded by the PTMA gene. Prothymosin alpha is expressed in many tissues, not only in the thymus, and its functions include nuclear roles in chromatin-related processes. The 28-residue fragment corresponds to the N-terminal portion of that precursor. How the cleavage occurs and how the fragment's concentration is regulated remain open questions; circulating amounts are small and difficult to measure reliably with routine assays.
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C129H215N33O55 | Calculated for the acetylated 28-residue peptide |
| Appearance | White to off-white powder | Lyophilized solid recovered from aqueous buffer |
| Solubility | Freely soluble in water | Typically dissolved in water or buffer before use |
| Typical storage | -20 C or below, desiccated | Protect from light and avoid repeated freeze-thaw cycles |
| Identity testing | Reverse-phase HPLC with mass spectrometry | Retention time and measured mass confirm the sequence |
Identity and purity are usually checked by reverse-phase high-performance liquid chromatography, which separates the intact chain from truncated products, together with mass spectrometry for confirmation of the expected mass. Peptide mapping after enzymatic digestion and amino acid analysis add sequence-level evidence. Release testing also covers water content, residual solvents, and counter-ions, all of which influence measured mass and stability. Related-peptide limits are commonly expressed as a percentage of total peak area, with individual unspecified impurities held below a lower threshold.
The lyophilized peptide is a white to off-white powder that dissolves freely in water and in aqueous buffers near neutral pH. Because the molecule carries a net negative charge under physiological conditions, saline and phosphate solutions are the usual vehicles, while strongly acidic media are avoided. Stock solutions are commonly divided into small aliquots so that repeated freezing and thawing can be limited, since cycling may encourage aggregation. Solubility in organic solvents is poor and those solvents are seldom used as primary diluents.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
Storage recommendations center on low temperature, dryness, and protection from repeated freezing and thawing. The intact powder is commonly held at 20 degrees below zero Celsius or colder, while a working solution is divided into single-use aliquots to limit freeze-thaw cycles. Buffered saline or phosphate-buffered saline at neutral pH is frequently used as a diluent. Light sensitivity is not well documented, yet amber vials or foil wrapping are common practice for long-term storage of peptide stocks.
Identity and purity are assessed with a small set of standard peptide methods. Reversed-phase high-performance liquid chromatography separates the main peak from truncated or oxidized species, and its area percentage is the usual purity measure. Mass spectrometry confirms the observed molecular mass against the expected value, while amino acid analysis or peptide mapping checks composition and sequence. Specifications for research-grade material are often stated as 95 percent or higher, though the exact limit depends on the supplier and the intended use.
Laboratory supplies of the peptide usually arrive as a lyophilized powder in sealed vials. The powder is hygroscopic, so a vial should be allowed to reach room temperature before it is opened to prevent condensation on the contents. Weighing and transfer are best performed in a low-humidity environment with clean tools. Once dissolved, the solution should be mixed gently rather than vortexed, because foaming and shear can reduce recovery of the peptide.
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. Subsequently, Derjaguin and his collaborators by applying Bradley's surface force law to an elastic half space, confirmed that as the Tabor parameter increases, the pull-off force falls from the Bradley value
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Genetic testing for Huntington's disease has raised several ethical issues, which include defining how mature an individual should be before being considered eligible for testing, ensuring the confidentiality of results, and deciding whether companies should be allowed to use test results for decisions on employment, life insurance or other financial matters. There was controversy when Charles Davenport proposed in 1910 that compulsory sterilization and immigration control be used for people with certain diseases, including HD, as part of the eugenics movement. In vitro fertilization has some issues regarding its use of embryos. Some HD research has ethical issues due to its use of animal testing and embryonic stem cells. The development of an accurate diagnostic test for HD has caused social, legal, and ethical concerns over access to and use of a person's results. Many guidelines and testing procedures have strict procedures for disclosure and confidentiality to allow individuals to decide when and how to receive their results and also to whom the results are made available. Insurance companies and businesses are faced with the question of whether to use genetic test results when assessing an individual, such as for life insurance or employment. The United Kingdom's insurance companies agreed with the Department of Health and Social Care that until 2017 customers would not need to disclose predictive genetics tests to them, but this agreement explicitly excluded the government-approved test for Huntington's when writing policies with a value over £500,000.
Sources: en.wikipedia.org
The brand became a well-established franchise in the Philippines, where it began in 1975 under the ownership of the country's largest food conglomerate, San Miguel Corporation, primarily promoting their San Miguel draft beer. Beginning with a restaurant located on Makati Avenue in Makati, the restaurant expanded rapidly in Metro Manila, with most of its outlets offering live music. San Miguel had difficulty maintaining the consistency of the branches, and ultimately sold the franchise in 1987 to International Family Food Services, Inc. (IFFSI), a group led by the family of sports executive Leo Prieto. In 1997, it had evolved into mostly a fast-food franchise. The brand was reengineered as a family-oriented casual dining brand in 2003. In 2004, Shakey's partnered with Sports Vision for the launch of the Shakey's V-League, one of the pioneering volleyball leagues in the country. The Shakey's Super League was formally launched on August 16, 2022, at the Shakey's Pizza Aseana City outlet in Parañaque. This marks the return of Shakey's Pizza in Philippine volleyball since they served as the title sponsor for the Shakey's V-League (now Premier Volleyball League) from 2004 to 2017. As of early 2015, there were 153 Shakey's outlets in the Philippines, more than double the number remaining in the United States. In March 2016, the Century Pacific Group and the Singapore-based GIC Private Limited acquired the majority shares of IFFSI from the Prieto family, which will retain a minority interest in the company.
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Psychological Depression Suicidal ideation Nightmares Apathy, anhedonia, or dysphoria Anxiety, especially social anxiety Decreased alertness, awareness, and wakefulness Impaired attention and concentration Fatigue Malaise Drowsiness Restlessness Cognitive and memory impairment Derealization or depersonalization, as well as mild psychosis Sexual dysfunction including impaired libido, desire, and drive Physiological Dizziness, lightheadedness, or vertigo Miosis or pupil constriction Xerostomia or dry mouth Gastrointestinal disturbances such as diarrhea or constipation Headache or migraine Myalgia or muscle aches, arthralgia or joint pain, or paresthesia ("pins and needles") Restless legs syndrome (RLS) Parkinsonian symptoms such as muscle tremors, rigidity, hypokinesia, or balance or postural instability Akathisia, ataxia, dyskinesia, as well as even tardive dyskinesia or dystonia Bell's palsy or facial paralysis Sexual dysfunction Hyperprolactinemia Gynecomastia in males, amenorrhoea or absence of menstrual cycles in females Bradycardia Hypotension Orthostatic hypotension Hepatitis, hepatotoxicity, or liver dysfunction or damage Pancreatitis Warm autoimmune hemolytic anemia or deficiency in red blood cells (RBCs) Myelotoxicity or bone marrow suppression, potentially leading to thrombocytopenia, blood platelet deficiency, leukopenia, or white blood cell deficiency Hypersensitivity (e.g., lupus erythematosus, myocarditis, or pericarditis) Lichenoid reactions (e.g., skin lesions or rashes) Pallor
Sources: en.wikipedia.org
It is a 28-amino-acid peptide originally purified from a bovine thymic extract and later produced synthetically. It is studied mainly for its effects on immune cell function.
No. The two peptides share part of a name but differ in length, sequence, and net charge. Literature searches that treat them as one compound return misleading results.
Solid-phase peptide synthesis is the usual route, and recombinant expression has also been described. Both approaches produce material matching the natural sequence.
Thymosin fraction 5 is a mixture of many peptides obtained from thymus tissue, while thymosin alpha 1 is a single defined 28-residue molecule. The two names appear together in older literature because the purified peptide was first obtained from that mixture.